This invention relates generally to a rotary crop residue spreader for an agricultural combine, and more particularly, to a spreader which utilizes a pivotally mounted elongate tubular support element for supporting at least one rotary crop residue accelerator and a crop residue deflector in cantilever relation to the accelerator, the spreader being positionable in at least one spreading position for receiving a flow of crop residue discharged from a rearwardly facing opening of the combine and accelerating and discharging it over a swath of an agricultural field, and at least one alternate position wherein the spreader is located such that at least a substantial portion of the residue flow from the combine will bypass or not be spread by the spreader for deposition on the field in windrows and which alternative position provides easier access to rear areas within the combine.
Currently, combines and some other harvesting machines typically include a straw chopper and/or straw spreader for disposing of straw separated from the harvested crop by the threshing mechanism onto the crop field. In addition, some combines have a chaff spreader for spreading the chaff separated from the grain by the cleaning apparatus or system. In some combines, the straw and chaff spreading functions are performed by a single spreader. Reference, Matousek et al. U.S. Pat. No. 5,797,793, issued Aug. 25, 1998, to Case Corporation; and Aubry et al. U.S. Pat. No. 6,238,286, issued May 29, 2001 to Deere and Company, which patents disclose vertical and horizontal crop residue spreaders, respectively, operable for performing assorted of the above-described spreading functions.
Often, when harvesting corn, it is desirable to spread the corn cobs, which are separated from the crop by the threshing mechanism and thus are part of the straw, evenly over the field. However, it is well known that the knives or blades of straw choppers can be more quickly dulled and more often broken by handling corn cobs, due to their large size and tough composition. As a result, while it is desirable to have the capability to spread tough crop residue such as corn cobs evenly over a combine""s swath, it may also be desirable to do so without chopping the cobs. As a spreader, it is desirable to utilize apparatus which does not clog, bunch or require cleaning. Additionally, when spreading, it is most desired to do so evenly, that is, to spread the crop residue uniformly over the swath of the combine, including the center of the swath directly behind the combine. This can be accomplished by allowing some of the crop residue to fall through or bypass the spreader so as to land on the ground under the spreader, but a problem that has been observed is that this crop residue can bunch up and fall as clumps onto the field, instead of being spread evenly. Also, crop residue entering the spreader can become jammed or caught in crevices and bend over edges, called xe2x80x9chairpinningxe2x80x9d, so as to require periodic manual removal.
As another capability, it is desirable for a crop residue spreader to be positionable in a non-spreading position such that crop residue can exit the combine and form a narrow windrow on the field behind the combine.
Additionally, from time to time, the combine""s threshing mechanism which separates the grain from straw and stalks, and the cleaning system which separates the grain from the pods and husks, require cleaning, adjustment, and/or maintenance which requires access thereto. Crop residue spreaders are typically mounted on the rear end of a combine in position for receiving a flow of crop residue from a rearwardly facing opening rearwardly of the cleaning system, and/or straw discharged through a downwardly or rearwardly facing space above the rearwardly facing opening. This location can make it difficult and time consuming to access aspects of the threshing and cleaning systems. In some instances, such access even requires removing the spreader and/or chopper.
Thus, what is sought is an improved crop residue spreader positionable in at least one operational or spreading position wherein straw, stalks, cobs, as well as chaff can be spread thereby; at least one position wherein straw can be windrowed; and at least one position wherein easy and convenient access to the threshing and cleaning apparatus of the combine is provided, the spreader and/or chopper being easily movable between the various positions, and lockable in at least one of the spreading positions. It is also sought to provide a spreader which is simpler to construct, yet is strong and robust, and provides an even spreading capability, and which is less likely to become clogged and/or drop undesired clumps of crop residue onto a field.
According to one preferred aspect of the invention, a support for a crop residue spreader for an agricultural combine is disclosed. The support utilizes an elongate tube, preferably of unitary construction, including a center portion and a pair of legs extending outwardly in opposite directions from the center portion, each of the legs including an end portion opposite the center portion and an intermediate portion disposed between the center portion and the end portion. Each of the end portions includes a pivot element, the pivot elements being coaxially aligned about a pivotal axis for pivotal connection to a rear end of the combine. Each of the intermediate portions includes a mounting element for supporting a rotatable crop residue accelerator thereon such that the crop residue accelerators will be located in side-by-side relation on the tube. Additionally, the center portion includes at least one mount for mounting a pair of crop residue deflectors in cantilever relation to the tube in position so as to extend partially around the crop residue accelerators, respectively. An advantage of the support is the simplicity of construction and strength and rigidity, the tube being bent as required to position the pivot elements and crop residue accelerators as desired or required for a particular application or capability, the bends enhancing torsional rigidity and strength. The end portions of the tube preferably have an outer cylindrical shape and are axially aligned to serve as the pivot elements. And, the crop residue deflectors function to guide flows of crop residue as they are accelerated and discharged from the spreader by the accelerators, the cantilever mounting providing the sole attachment of the deflectors to the spreader, such that no location is present for crop residue to snag or hairpin and form clogs or clumps. Preferably, the legs of the tube are angularly related forming a V-shape, and the tube is a unitary member, and the deflectors are mounted and supported in back-to-back relation for enhanced strength and resistance to bending.
According to another preferred aspect of the invention, the spreader is pivotally movable between at least one spreading position wherein the spreader is located rearwardly of a rearwardly facing opening of the combine for receiving at least a substantial portion of a crop residue flow discharged therethrough, and at least one second or additional position wherein the spreader is located beneath the rearwardly facing opening in a position such that a substantial portion of the residue flow discharged through the opening will bypass the spreader. This allows the residue discharged through the opening, as well as straw discharged through a space thereabove to be deposited directly onto the field behind the combine, forming a windrow. Additionally, in the second or additional position, the spreader is located so as to allow easy and direct access to the rearwardly facing opening and the space thereabove, for inspection, service, and maintenance purposes. The spreader can be retained in the spreading position using any suitable means, such as pins, detents, locks, and the like, and can be held in the other or non-spreading position by gravity, as desired.